1. Technical Field
The present invention relates to an ink set, ink container, inkjet recording method, recording device, and recorded matter, and particularly relates to an ink set, ink container, inkjet recording method, recording device, and recorded matter, which can form a film with metallic gloss.
2. Related Art
Conventionally, gold bronze powder made of brass and aluminum fine powder and the like, printing ink with silver powder pigment, foil press printing using metal foil, and a thermal transfer method using a metal foil have been used to form a film with metallic gloss on printed matter.
However, with a coating film consisting of a printing ink that uses gold bronze powder, or silver powder, the average particle size of the metal powders that are used will be large, between 10 μm and 30 μm, and thus a flat metallic finish can be obtained, but achieving a mirror surface gloss is difficult. Furthermore, with the foil press or thermal transfer methods that use a metallic foil, an adhesive is applied as a printing carrier, and a flat metallic foil is pressed thereon, the recording carrier and the metallic foil are heated to cause firm adhesion, and the metal foil and recording carrier are thermally fused together. Therefore, a relatively good gloss can be achieved, but there are many manufacturing steps, and pressure and heat are applied during the manufacturing process, so the recording medium is restricted by the limited recording media that are resistant to heat and deformation.
In recent years, many examples of applying inkjet technology to printing have been seen, and one example of application is metallic printing. For example, JP-A-2002-179960 discloses technology of forming a metal film on a plastic spherical particle surface, and printing an ink composition that contains a pigment using inkjet printing. However, in order to obtain a highly metallic gloss, the spheres must be deformed and flattened to make a smooth surface, and with this technology, heating and pressing with a roller must be simultaneously performed. Therefore, the equipment and manufacturing processes are inevitably complicated by this point, and the recording medium is also restricted.
Furthermore, JP-A-2003-292836 and JP-A-2003-306625 disclose technology that uses an ink composition wherein a colloid of a precious metal such as gold or silver is dispersed. However, if the particle size of the precious metal colloid is small, within a range between several nanometers and several tens of nanometers in order to give priority to dispersion stability, discoloration caused by plasmon absorption will occur, and the ink composition will not provide a metallic gloss. In this case, after the coating film is dried, a metallic gloss is achieved by heating to 150° C. or higher in order to fuse the colloid particles together. Furthermore, if the particle size is increased in order to give priority to metallic gloss, the dispersion stability will be degraded, and problems with conglomeration and settling will be inevitable, and the storage life of the ink composition will be significantly reduced. Furthermore, although trivial, using precious metals as a material will increase the cost of the ink composition, so use will be restricted to applications with high added value, and there are disadvantages related to cost.
Furthermore, a metallic ink composition is known which uses a blend of metallic pigment and colorant as one ink composition, but when printing with this method, there are problems with the metallic pigment and the colorant separating and only the metallic pigment settling during storage of the ink composition, and this is a cause of printing defects such as the creation of a nonuniform image with variation and color loss occurring because only the colorant is absorbed into the recording medium leaving only the metallic pigment on the surface.